[milo] {buildbucket,buildbot,swarming,logdog} -> backends/*.

milo/appengine/logdog/internal/stream.proto

Index: milo/appengine/logdog/internal/stream.proto
diff --git a/milo/appengine/logdog/internal/stream.proto b/milo/appengine/logdog/internal/stream.proto
deleted file mode 100644
index 3da81ba15468d0f975c60f04da0198481f4d71d5..0000000000000000000000000000000000000000
--- a/milo/appengine/logdog/internal/stream.proto
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2016 The LUCI Authors. All rights reserved.
-// Use of this source code is governed under the Apache License, Version 2.0
-// that can be found in the LICENSE file.
-
-syntax = "proto3";
-
-package internal;
-
-import "github.com/luci/luci-go/common/proto/milo/annotations.proto";
-
-// Item is a full annotation protobuf state item. It is used to serialize and
-// deserialize Step and associated fetch data into memcache.
-message CachedStep {
-  // Step is the root annotation step.
-  milo.Step step = 1;
-
-  // Finished is true if this is the last annotation protobuf in the stream.
-  bool finished = 2;
-}